Since CET-4 （College English Test Band 4） is a high-stake test in China, the majority of students take passing CET-4 as their motivation of learning English. In this paper, the author would like to argue that CET, a...Since CET-4 （College English Test Band 4） is a high-stake test in China, the majority of students take passing CET-4 as their motivation of learning English. In this paper, the author would like to argue that CET, as a motivation of learning English and an assessment tool, is only a practical and realistic choice for Chinese government to satisfy the national and personal requirements of international development. Students are not learning English for passing CET, but gaining the benefits brought by English. However, the influence from English or western cultures accompanying with the high-stake of CET will form a new national identity of college students-study for motherland.展开更多
The Pythagorean triples (a, b | c) of planar geometry which satisfy the equation a<sup>2</sup>+b<sup>2</sup>=c<sup>2</sup> with integers (a, b, c) are generalized to 3D-Pythagorean ...The Pythagorean triples (a, b | c) of planar geometry which satisfy the equation a<sup>2</sup>+b<sup>2</sup>=c<sup>2</sup> with integers (a, b, c) are generalized to 3D-Pythagorean quadruples (a, b, c | d) of spatial geometry which satisfy the equation a<sup>2</sup>+b<sup>2</sup>+c<sup>2</sup>=d<sup>2</sup> with integers (a, b, c, d). Rules for a parametrization of the numbers (a, b, c, d) are derived and a list of all possible nonequivalent cases without common divisors up to d<sup>2</sup> is established. The 3D-Pythagorean quadruples are then generalized to 4D-Pythagorean quintuples (a, b, c, d | e) which satisfy the equation a<sup>2</sup>+b<sup>2</sup>+c<sup>2</sup>+d<sup>2</sup>=e<sup>2</sup> and a parametrization is derived. Relations to the 4-square identity are discussed which leads also to the N-dimensional case. The initial 3D- and 4D-Pythagorean numbers are explicitly calculated up to d<sup>2</sup>, respectively, e<sup>2</sup>.展开更多
Transcription factors and DNA/histone modification enzymes work in concert to establish and maintain cell identity. CD4^＋ and CD8^＋ T cells are key players in cellular immunity with distinct functions. Recent studie...Transcription factors and DNA/histone modification enzymes work in concert to establish and maintain cell identity. CD4^＋ and CD8^＋ T cells are key players in cellular immunity with distinct functions. Recent studies offer novel insights into how their identities are established in the thymus and maintained in the periphery during immune responses. During thymic maturation, Thpok, HDAC1 and HDAC2 guard CD4^＋ T cells from activation of CD8^＋ cytotoxic genes, and Tcfl and Left utilize their intrinsic HDAC activity to shut down CD4^＋ lineage-associated genes in CD8^＋ T cells. In activated CD4＋ T cells, Tcfl and Left act upstream of the Bc16-Blimpl axis to direct differentiation of follicular helper T （Tfh） cells, and prevent diversion of Tfh to IL-17-producing cells. In parallel, T-bet, together with Eomes or Blimpl, ensures proper induction of the cytotoxic program in CD8^＋ effectors elicited by acute infection, and prevents generation of pathogenic, IL-17-producing CD8^＋ effector T cells. Antigen persistence due to chronic viral infection leads to CD8^＋ T cell exhaustion. A portion of exhausted CD8^＋ T cells has the capacity to activate the Tfh program in a Tcfl-dependent manner. Those Tfh-like CD8^＋ T cells exhibit enhanced proliferative capacity in response to PD-1 blockage therapy and are more effective in curtailing viral replication. Thus, dissecting the molecular aspects of T cell identity, during development and immune responses, may lead to new therapies for treating autoimmunity, tumors, and persistent infections.展开更多
Germinal centers(GCs)are essential for the establishment of long-lasting antibody responses.GC B cells rely on post-transcriptional RNA mechanisms to translate activation-associated transcriptional programs into funct...Germinal centers(GCs)are essential for the establishment of long-lasting antibody responses.GC B cells rely on post-transcriptional RNA mechanisms to translate activation-associated transcriptional programs into functional changes in the cell proteome.However,the critical proteins driving these key mechanisms are still unknown.Here,we show that the RNA binding proteins TIA1 and TIAL1 are required for the generation of long-lasting GC responses.TIA1-and TIAL1-deficient GC B cells fail to undergo antigen-mediated positive selection,expansion and differentiation into B-cell clones producing high-affinity antibodies.Mechanistically,TIA1 and TIAL1 control the transcriptional identity of dark-and light-zone GC B cells and enable timely expression of the prosurvival molecule MCL1.Thus,we demonstrate here that TIA1 and TIAL1 are key players in the post-transcriptional program that selects high-affinity antigen-specific GC B cells.展开更多
文摘Since CET-4 （College English Test Band 4） is a high-stake test in China, the majority of students take passing CET-4 as their motivation of learning English. In this paper, the author would like to argue that CET, as a motivation of learning English and an assessment tool, is only a practical and realistic choice for Chinese government to satisfy the national and personal requirements of international development. Students are not learning English for passing CET, but gaining the benefits brought by English. However, the influence from English or western cultures accompanying with the high-stake of CET will form a new national identity of college students-study for motherland.
文摘The Pythagorean triples (a, b | c) of planar geometry which satisfy the equation a<sup>2</sup>+b<sup>2</sup>=c<sup>2</sup> with integers (a, b, c) are generalized to 3D-Pythagorean quadruples (a, b, c | d) of spatial geometry which satisfy the equation a<sup>2</sup>+b<sup>2</sup>+c<sup>2</sup>=d<sup>2</sup> with integers (a, b, c, d). Rules for a parametrization of the numbers (a, b, c, d) are derived and a list of all possible nonequivalent cases without common divisors up to d<sup>2</sup> is established. The 3D-Pythagorean quadruples are then generalized to 4D-Pythagorean quintuples (a, b, c, d | e) which satisfy the equation a<sup>2</sup>+b<sup>2</sup>+c<sup>2</sup>+d<sup>2</sup>=e<sup>2</sup> and a parametrization is derived. Relations to the 4-square identity are discussed which leads also to the N-dimensional case. The initial 3D- and 4D-Pythagorean numbers are explicitly calculated up to d<sup>2</sup>, respectively, e<sup>2</sup>.
文摘Transcription factors and DNA/histone modification enzymes work in concert to establish and maintain cell identity. CD4^＋ and CD8^＋ T cells are key players in cellular immunity with distinct functions. Recent studies offer novel insights into how their identities are established in the thymus and maintained in the periphery during immune responses. During thymic maturation, Thpok, HDAC1 and HDAC2 guard CD4^＋ T cells from activation of CD8^＋ cytotoxic genes, and Tcfl and Left utilize their intrinsic HDAC activity to shut down CD4^＋ lineage-associated genes in CD8^＋ T cells. In activated CD4＋ T cells, Tcfl and Left act upstream of the Bc16-Blimpl axis to direct differentiation of follicular helper T （Tfh） cells, and prevent diversion of Tfh to IL-17-producing cells. In parallel, T-bet, together with Eomes or Blimpl, ensures proper induction of the cytotoxic program in CD8^＋ effectors elicited by acute infection, and prevents generation of pathogenic, IL-17-producing CD8^＋ effector T cells. Antigen persistence due to chronic viral infection leads to CD8^＋ T cell exhaustion. A portion of exhausted CD8^＋ T cells has the capacity to activate the Tfh program in a Tcfl-dependent manner. Those Tfh-like CD8^＋ T cells exhibit enhanced proliferative capacity in response to PD-1 blockage therapy and are more effective in curtailing viral replication. Thus, dissecting the molecular aspects of T cell identity, during development and immune responses, may lead to new therapies for treating autoimmunity, tumors, and persistent infections.
基金We thank all personnel from the Toulouse animal facility CREFRE and from the flow cytometry,imaging,transcriptomics and bioinformatics technical platforms of INFINITy.M.D.D-M.is supported by ATIP-Avenir-Plan Cancer(C18003BS),ANR(ANR-20-CE15-0007)foundation ARSEP R19201BB,foundation ARC,La Ligue Contre Le Cancer and INSPIRE(Region Occitanie,Inserm and CHU Toulouse)M.T.is supported with a BBSRC core funding grant and a Wellcome Investigator award(200823/Z/16/Z).D.C.-S.is supported by Boehringer Ingelheim Fonds.
文摘Germinal centers(GCs)are essential for the establishment of long-lasting antibody responses.GC B cells rely on post-transcriptional RNA mechanisms to translate activation-associated transcriptional programs into functional changes in the cell proteome.However,the critical proteins driving these key mechanisms are still unknown.Here,we show that the RNA binding proteins TIA1 and TIAL1 are required for the generation of long-lasting GC responses.TIA1-and TIAL1-deficient GC B cells fail to undergo antigen-mediated positive selection,expansion and differentiation into B-cell clones producing high-affinity antibodies.Mechanistically,TIA1 and TIAL1 control the transcriptional identity of dark-and light-zone GC B cells and enable timely expression of the prosurvival molecule MCL1.Thus,we demonstrate here that TIA1 and TIAL1 are key players in the post-transcriptional program that selects high-affinity antigen-specific GC B cells.
